#!/usr/bin/perl -w

use strict;
use DB_File;

$| = 1;

unless @ARGV { die "No filename argument provided"; }
my $file = shift @ARGV;

# here's this line again:
tie my %IDS, "DB_File", $file or die "Can't open $file: $!";

# and this block is the same as I used for testing above
for (keys %IDS){
	print "\n\n$_:\n";
	for my $key (@{$IDS{$_}}){
		while (my($k, $v) = each %{$key}){
			print "$k => $v\n";
		}
	}
}